1. Field of the Invention
The present invention relates to a method and apparatus for preventing degradation to unexpected or unintended out-of-spectrum services over copper pairs, while permitting intended services to operate.
2. Acronyms
The following acronyms and abbreviations are used throughout the specification. For brevity, the definitions are summarized as follows:
xDSL(generic or any kind of) Digital Subscriber LineADSLAsymmetric Digital Subscriber LineBLCBridge Lifter CoilCOCentral OfficeDDSDigital Data ServicesISDNIntegrated Services Digital NetworkPOTSPlain Old Telephone Service
3. Description of Background Information
Certain levels of service, demanding a certain bandwidth at a certain portion of the available spectrum, are provided over copper pairs providing the physical connection to a telephone company's Central Office (CO). Typical services available over copper pairs at present include regular analog telephone service (Plain Old Telephone Service—POTS), burglar alarm service, various types of Digital Subscriber Lines (xDSL) including Asymmetric DSL (ADSL), Digital Data Services (DDS), ISDN service, etc. In the context of the present specification, “telephone service lines” includes telephone lines used for burglar alarms.
Different digital services occupy different portions of the spectrum from each other, and digital services tend to occupy a larger portion of the available bandwidth at a higher frequency portion of the spectrum than regular analog telephone services or burglar alarm services (i.e., low bandwidth-low frequency services). When one service or a set of services is assigned to a customer over a loop (a copper pair), no provision is typically made for support, monitoring, or upkeep of any services over that line other than those assigned.
Accordingly, if a loop intended for one service or a limited set of services (e.g., a low-bandwidth low-frequency service alone, or the same in combination with one or more digital services) is unexpectedly used for an additional service, usually having a different spectrum (e.g., one or more additional digital services), the likelihood of unsatisfactory service is high. That is, no support is provided if the line or loop is used for a service other than those assigned to the loop. Moreover, even if the unexpected use of an additional service over a loop intended for a first service is detected, there is no easily implemented or economical manner of taking remedial action to limit or return the loop to the intended service.